Fluid relief device



United States Patent FLUID RELIEF DEVICE Jack A. Britten, 11720 Edgewater Drive, Lakewood 7, Ohio Filed Sept. 22, 1955, Ser. No. 535,862

11 Claims. (Cl. 137-73) circular valve seat, and a spring holds a valve body against the seat to resist pressures below the predetermined limit for which the spring is set. A passage conmeets the pressure chamber portion to the exhaust chamberportion. This passage is plugged by a low fusion metal as. other suitable heat responsive material so that when predetermined temperature limits are exceeded the plug melts or is released opening the passage between the chamber portions. Thus the exhaust chamber portion receives fluid released from the pressure chamber portion through eitherthecircular seat of the pressure control system or the passage of thetemperature control system.

One. of the principal objects of this invention is to provide a relief valve of the character mentioned having a housing of generally cylindrical external contour and of materially reduced weight and cost of manufacture with a squared or parallel flat sided wrenchreceiving section or part so that the housing may be turned by a wrench. More specifically it is sought to provide a generally' cylindrical contoured valve housing of relatively thin wall section having an integral internal reinforcing web in the Vicinity of the lands of a wrench receiving portion to provide a valve of reduced weight and cost of manufacture which has sufiicient strength in the vicinity of the wrench receiving section or lands to prevent collapsing of the housing walls by wrench applied pressures.

.'As .an additional object of the invention the quantity of material required to form a temperature-pressure relief valve is reduced with attendent savings in weight and manufacturing cost due to the shortening of the length of the valve.

The provision of a generally cylindrically contoured housing having an enlarged wrench receiving section or part which has parallel wrench receiving surfaces or lands provides a valve which may be installed by an unskilled or uninstructed person without danger of damage to the valve; Such an unskilled person would only apply a wrench to the wrench receiving part. It is, therefore, a further object of the invention to provide a valve having a construction which will induce an operator to apply a wrench only to the strongest portion of the housing which portion is in the vicinity of the reinforcing web. 7

A further object of the invention is to provide a relief valve having the valve seat of the pressure relief structure in the plane of one or more of the attaching bosses to thereby reduce the overalllength of the valve housing as well as to strengthen it.

a valve in which the threaded bosses for the fluid openings which are transverse to the housing axis overlap one another axially and also are located in the vicinity of the reinforcing web to strengthen the housing and increase its resistance to fracture. More specifically it is sought to provide increased housing strength by 10- eating the hollow or tubular attaching bosses at difierent points along the length of the housing axis spaced less than the diameter or other transverse dimension of the smaller of such bosses so that such bosses overlap one another along the housing length although their axes are longitudinally spaced.

'A still further object is to provide a combined temperature pressure relief valve in which the fusible plug constituting the temperature relief element is replaceable from the outside of the valve casing without removing the latter from its installed position and without disturbing or removing the pressure relief valve assembly. More particularly this aspect of the invention is concerned with the provision of an auxiliary or appendage boss integral with one of the fluid opening bosses, the auxilary boss having an internal chamber connected to the pressure and exhaust chambers and adapted to receive the fusible sealing plug.

Further objects and advantages will be apparent from' I p the following detailed description of a preferred embodiment representing the bestmode of practicing the invention and from the appended drawings which are a part of the specification. 1

In the drawings:

I Fig. 1 is a front elevational view of the relief valve partly in section and with-parts broken away showing;

the cap or closure, the reinforcing web, the housing boss portions for receiving or attaching 'to inlet exhaust and Fig. 3 is a cross sectional view taken substantially" along the line 33 of Fig. 2 showing the reinforcing web, the wrench receiving portion, the inlet opening, and

the temperature relief assembly;

Fig. 4 is a rear elevational view of the complete valve showing the-flat wrench land portions of the housing surrounding the internal reinforcing web; and

Fig. 5 is a bottom view of the valve showing the shape of the wrench receiving section.

The valve of the present invention as embodied in the structure shown in the drawings, representing the best known mode of practicing the invention, comprises a' hollow chambered body or housing 1 formed as by machining or forging but preferably and more economically by casting brass, aluminum or other suitable metal. The internal chamber of the body housing is divided by an integral transverse web or partition 20 into a pressure chamber 2, shown beneath the partition, and an exhaust chamber 3, shown above the partition. It is understood, of course, that in suitable applications the valve may be inverted from the position shown in the drawings or used horizontally or in any other desired angular relationship to the other components of the fluid system. The part of the housing which defines the pressure chamber portion is formed with integral threaded tubular bosses the internal passages of which are continuous with the pressure chamber 2. The particularvalve illustrated is intended for use with a conventional Patented Dec. 27, 1950 hot water heater tank. Accordingly'the lower end ofthe housing body is continuous with or in the form of an externally threaded coaxial attaching boss 11 which may be screwed into the internally threaded bunghole or outlet opening of a conventional water heater tank. On one side of the housing is an integral laterally projecting boss 8 having an internal passage 4 continuous with the pressure chamber 2, this passage constituting the outlet through which the hot water from the tank heater is suppl'ied .to the system protected by the relief valve. The boss 8 may be externally threaded, provided with a fitting to receive a union nut or, as shown, threaded 6 in ternallygto receive the conventionally threaded end of" a water distribution pipe. p

Also projecting laterally from the housing body 1 but with its axis spaced axially along the axis of the housing body from the axis of the boss 8 a distance less than the diameter of the boss 8 (preferably about half such diameter) is an integral tubular boss 22 which defines an out:- let passage 23 co'ntinuous with the exhaust chamber, 3 above the partition 20. The axis of the exhaust boss 22 is rotated about 90 degrees about the housing axis relative to the axis of the outlet boss 8 so that the plane of the transverse partition 20, more specifically the plane of the valve seat formed in the partition, as will be later described, extends through the outlet passage 4 and also through the exhaust passage 23 in parallel relation to the axes of the bosses in which such passages are formed. Thus the plane of the reinforcing partition (and valve seat) lies within the outlet and exhaust passages with portions offeach of such passages being disposed on positesidesjof the partition plane; By this arrangement maximum strength is imparted to the valve and it is better able to withstand the stresses to whichit is subjected when 'pipesiare screwed intothe bosses "8 and 22 than in;the ease of a conventional valve.

,Th'efexhatlst b03522 "may be internally threaded, 'as ifi dicated' tit-'18; to receive the threaded "end of a suitable discharge conduit for carrying 06 any fluid released into the exhaust chamber 3 through the pressure relief passage in the partition or through the drilled intersecting'tem- V perature "relief passages.

A flanged cap 24 having a noncircular he'x top and downwardly extending externally threaded portion 25 is insertedin-threaded engagement with internal threads 26 which are formed inside a top opening of 'the housing which is continuous with the top of the exhaust chamber portion 3. The cap 24; forms a 'fluid seal for the exhaustchamber portion through coaction with Washer 21 disposed between the cap flange and the upper end of the.

housing. A valve adjusting screw plug '27 having external threads 28 is placed in threaded engagement with the threaded section 26 of the housing, inwardly of the cap 24.

A valve seat 31 is formed in the central integral web or partition 20 which divides the housing 'interior'into the upper exhaust and lower "pressure portions mentioned. The valve seat defines a circular opening 32 which con- 'nects the housing chamber pressure'and exhaust portions 7 2 and-3. A valve body indicated 'generally'at 33is held in yieldable sealing engagement against the valve seat 31 by a helical coilcomp'ression spring'29 reacting against the screw plug 27. p a V The valve adjusting screw plug has an annular relief 7 area34-on its under side which receives a circular spring receiving disc-or seat member 35. The spring receiving member '35 is a shallow cupshap'ed brass stamping and on its under :Sidejs formed to definefan'annular relief "36 Which receives and locates upper end 37 of the spring 29.

The spring 'adjusting screw 27 has a frusto-conical pin extensioh'3tfdirecteddownwardly the center of annular reliefarea 341th provide point contactbearing in depressed center 38"of'the'disc 35, being an annularclearance surrounding the pin .between thescrew plug 27 andthe 4 the spring adjustment screw 27 to reduce friction upon rotation of the plug 27 relative to the spring and spring receiving member 35. The point contact permits the valve body to be guided into complete and accurate engagement with the valve seat and prevents objectional internal stress or binding conditions which might otherwise exist.

The housing 1 is principally of cylindrical curvature externally, or substantially so, and inner surfaces 39, 40 define, respectively, the generally circular sectioned pressure and exhaust chamber portions 2 and 3. The pressure chamber portion 2 is defined by the inner surface 39 of circular section or having circular curvature substantially throughout its length from the bottom 12 of the housing to the partition 20. A suitable rotary tool may be introduced through the top end opening of the housing 1 and passed downwardly, axially through the exhaust chamber portion to machine a smooth cylindrical inner surface 40. The web or partition 20 has an upper surface whichdefines an annular channel 15 surrounding the valve seat 31. The channel 15 may be machined by the same rotary tool which machines the inner surface 40 to form the valve seat 31 in the same operation as the inner surface 40. The smooth inner surface 40 thus formed'serves to guide the valve body 33 during axial movement when the valve is unseated in response to excessive pressure in the pressure chamber or seated in response to pressure exerted by the biasing spring 39. h h

The valve body 33 has an internally threaded 'axial'pas sage 43 which receives the threaded reduced diameter sec; tion45 of a plug member 44. Flangedend portion 46 of the plug has a pair of relieved areas or flats 47 to provide surfaces to receive a wrench or-the like to tighten the threaded engagement of the plug an'd'the valve body.

An annular flat-faced washer 52 o'f'rubber, polyethylene or other suitable plastic materialis am saw'sna forms apart of the valve body as by beihgclaniped between the fiat end face of the valve bea ss ana theange arms.

, outwardly through the exhaust passage 23.

escape passage releases fluid fr'o'mthe pressure-chamber 2 into theex-haust chamber 3 when thetefniperatur'e "of the device exceeds a predetermined limit. Such escape passage comprises intersecting drill holes '41 and-41mmmunicating, respectively, with thefp'ressure and exhaust chambers. The hole 41--is drilled into the chamber 2 in a direction normal to and intersecting "the longitudinal axis of the body housing 1 througha supplemental boss 48 located in the angle between the exhaust passage bliss g 22 and the housing'body; This supplemental boss '48is I integrally joined to both the body housing and thee):-

springreceivi'ng cup 35. 'Ihe ppint cbntact,so formed,

, transmitsaxial biasing pressure between the spring '29 and haust boss 22, being the same length as'but 'narrdw'er than the latter as'shown'in Figures 3 and '5. The passage 42 is formed by inserting a drill "through theopen to'p Ofthe body housing *1, the axi's'of the'drillbeing disposed" at'an angle such a's about20 degreesto and, iiiter'secting the axis of the body housing. The'upperend'of the chilled pasagei tz thus'opens into the 'exhaustiihamber 3a'diaceiit and outside of the valve seat 31 'Of thFPfessiire relief structure. 7

the intersection of the pass 's 41, 4 2 an enlarged chamber is provided as by a westerners 49 toreceive a fuse plug 50. This plug is of cylindrical shapeandcomprises 'any suitable low melting 'point 'rne'tal alloy suclras ,theeutectic-alloy'ofabout the following compositioni szjsas ni- 32% Pb' 15.5%.Sn

having a melting point of about 203 degrees The outer end of the drilled through passage in the supplemental boss 48 is threaded to receive a cap screw 51 which bears axially against the fuse plug 50 to seat the inner end of the latter against a radial shoulder 53 at' the inner end of the counterbore 49, thereby sealing the passage 41 from both the escape passage 42 and the tapped opening through the face of the boss 48. Thescrew 51 may be used to apply deforming pressure to the plug so that the latter is made to fill the counterbore and sealingly engage the walls.

Upon an increase in temperature of the fluid in the hot water tank or other system protected by the present valve above a predetermined temperature valve, such as the 203-degree F. temperature mentioned, such temperature being transmitted to the housing body 1 by conduction as through the threaded attaching boss 11, the temperature of the plug 50 is raised above its melting point and the plug is released through the escape passage 42, thereby clearing the intersecting passages for the escape of high pressure fluid from the pressure chamber 2 into the exhaust chamber 3. Without removing the housing body from its connection in the fluid system and without disturbing or disassembling the pressure relief assembly, to be later described, the temperature relief plug 50 can be readily replaced by simply removing the cap screw 57, inserting a new plug into the chamber 49 and reinserting the retaining cap screw. The present invention thus provides an external access fuse arrangement which simplifies service of the valve in-use as well as-original assembly. As an additional feature the location of the supplemental boss 48 in the angle between the laterally projecting exhaust boss 22 and the housing body 1 strengthens the entire valve structure.

"Intermediate the ends of the housing there is formed a portion or section of generally squared configuration having cylindrically surfaced portions both above and. below, in the provision of parallel wrench receiving surfaces or lands 56 and 57 and a flat surface 55 normal to the wrench lands. The wrench receiving section permits the generally cylindrically contoured valve to be rotated by a crescent or other suitable wrench.

The wrench land 55 is parallel to the plane of end face 59 of the threaded boss 8 so that a wide jawed wrench can be applied across the body 1 with one jaw of the wrench engaging the land 55. In general, the wrench receiving section of the housing body, comprising the flat lands 55, 56 and 57, 'is disposed between the plane'of the valve seat 31 and one of the threaded attaching bosses, here'the main attaching or inlet boss 11. A person installing or removing the valve is thus able to apply a wrench, other than a pipe wrench which is apt to mar or disfigure the valve, to the exterior of the valve to rotate the valve relative to the tank or other device with which the valve is associated.

To strengthen the housing walls the internal web 20 is located in the vicinity of the Wrench receiving section and may even lie within the wrench lands. Preferably the lower or pressure chamber face 58 of the web 20 lies in a plane which is substantially normal to the axis of. the housing 1 and to the planes of the wrench receiving surfaces 55, 56 and 57. A person installing a valve having web and wrench receiving portions thus located will, without instruction or supervision, normally apply a wrench to the strengthened and reinforced portion of the housing body rather than to one of the more collapsible end portions.

To provide a valve having a shortened longitudinal extent as well as to increase the strength of the housing, the boss 8 which defines the opening 4 is located so that the axis of such opening lies substantially in the plane of the web lower or pressure chamber face 58. Such location of the boss and the lateral passage or opening permits the reinforcing strength of the integral internal web 20 to give support to the housing walls at and adjacent the lines of connection between the walls and the base of the boss. wall collapsing pressures which may exist under wrench application. To close ofi the the exhaust chamber 3 from the outlet passage 4 the web 20 includes a vertical part 63 which extends longitudinally in the housing. This vertical or longitudinal web part 63 is cylindrically curved on that side which faces the exhaust chamber 3, such sidehaving a face that coincides with the surface 40 of the exhaust chamber. The other face of the web part 63 which closes off the upper half of the passage 4 at its inner end may be flat, as shown. Communication between the opening 4 and the pressure chamber 2 is through semi-circular opening 64 which has a crosssectional area substantially equal to the cross-sectional area of the fluid conducting passage of a conduit of sizeinforcing strength to resist wall collapsing pressures hasthus been provided.

In accordance with the patent statutes the principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction' being resorted to as desired, it being understood that the embodiment shown in the drawings and described above" is given merely for purposes of explanation and illustra-"- tion without intending to limit the scope of the claims to the'specific details disclosed.

What I claim and desire to secure by Letters'Patent of the United States is: v i

l. A fluid relief device comprising a hollow housing having internal pressure and exhaust chambers, means defining an opening between the chambers, a valve movable into and out of sealing relation to the opening, means biasing the valve normally to seal the opening and adapted to yield to a predetermined pressure differential between the chambers to permit the flow of fluid from the pressure chamber to the exhaust chamber, the housing being formed with openings into the pressure chamber for association with supply and use conduits and formed with an opening into the exhaust chamber constituting an exhaust, the housing being formed with intersecting passages one of which communicates with the pressure chamber and another of which communicates with the exhaust chamber, a fusible and deformable plug disposed in one of the intersecting passages, means engaging the plug to locate the latter in predetermined position in the passage in which it is received, said located plug extending across the intersection of the passages, and means actuatable to apply deforming pressure to the located plug whereby the plug fills and sealingly engages the walls of the passage in which it is received on both sides of said intersection and to hold the located and deformed plug against the locating means.

2. A fluid relief device comprising a hollow housing having an internal partition dividing the housing interior into pressure and exhaust chambers, said partition being formed with an opening through which the pressure chamber communicates with the exhaust chamber, valve means normally sealing the opening in the partition, the

housing being formed with integral bosses having passages" communicating with the pressure chamber, a supplemental boss projecting laterally from the housing body adjacent the partition, said supplemental boss being formed with internal intersecting passages one of which'commu'nicates with the pressure chamber and another of'which com- Thus the housing body is reinforced to resist mu h e with, the exhaustchamber, mee v s i p ssages a predete minedprei nre lfi tee iel s e lq ias fls df eing o med i h a .c.onnt e e prov ding-an. annular o. e cap rom he pre sure chambe nto, the-hal s; h u derloe ed be w en he te ection of: t e pa sa ham r, h .1 si lsil g o med; th e. hroug nd; one of the ch b r a fusible. plug i posed n the a e ex eadinst ein a o ide eneuinsl a lns de a ar counterbo e, sa dp nding' er ss the i ter ec on f; 5 ns nto he pres ur ch mbe m ns P di n ab the; passages, said laterally projecting supplemental boss meri the passage, a fu i e nd; d formabl p ug;

being formed with n access pas ge having n; externa Po e n e: P ssa e d r n s e tf i l fi opening through which the plug ijs insertable into its posi; passage wall, oneend of the plug being disposed against tion in the counterbore, and means receivablegip ac thenahutrnent, ascrew'threadedinto the through passage, cess opening to close the latter and, retainthe plug cap said screw being adapted upon tightening tov bear against tive, said pl g r aining m ans being; c uatable to fen e h Othern of h plu n apply n li r l g, Pr s r the plug into intimate bearing relation-to the shoulder thereto to confine the plug between the abutment and around the entire circumferential extent ofrithe latter the screw and to efiect a sealbetween the plugand the whereby to seal the counterboredpassage and to deform walls of the passage, the housing being formed with a he: plug into sealing engagement; with he, w ll ofthe relief Pa t s ng an h in n nd QPQRiBg counterbore on both sides of the. intersection. n the h gh p a dja n h ment t a p in -3. YA fluid relief device comprising a hollow housing etween such abu ment and the screw so that ai en having an internal partition dividing the housing interior p ning: of he relief passage; is closed and sealed by the into pressure and exhaust chambers, said partitionheing; plug upon deformation of the latter by sc e pressure, formed with an opening through which the pressure Charm. 0 and-the other end of the relief passage being in com-. ber communicates with the exhaust chamber, valve means uni a nr h-the exhaus ha ers normally sealing the opening in the partition, thehousingfi I a id lie 34 9 O t WP mp ng; being formed with integral bosses having passages com low h u ing, means the housing dividing the interior municating with the pressure chamber, a supplemental into p u a haus h Q r and formed with a boss projecting laterally from the housing body adjacent connecting p nge chambers, a pr ng biased the partition, said supplemental boss being formed with l e normally closing-said opening nd adapted to yield internal intersecting passages one of which communicates; pfe-detefmintidz fi er n l in allowing d with the pressure chamber and another of which vcomto e ape f hfiPQfiEiQ hambe .i he xl flmt. municates with the exhaust. chamber, one of said passages m m e h h u in b g orm d th a. tl lqfl l Pit being termed with aoolm rhore rovidingan annular eg xt ni ugfrqnlaa 'de qpe natq eu-insideopem houlder located between the-intersection of the-passages sr e PIG JJIQ e asib means. Pmv dih an fil end; one. of the chambers, a substantially cylindrical der- S Q llder inithepassage-facingtoward thesoutside openforrnable an d fusible plug disposed in the counterbol'c, 8, l s bl defo ne lep ug disposed ht -p l' sil g said. plug being of greaterjlength. axiallynof the counter and; ga s e l er; a; Screw h e h P8 e edip s age h n diameter and than the distance from a from t e outs e end nd pted up nin the shoulder across the intersection :of the passages and 0 be agai s h p xl EP YlBg form P e su ctrhe "s me/ ross sectional shapea the counterbored he e o o e he P usain t he s o in at esting; passage at such intersection, and means in one .of the -p m y seal efthe Ra e ean a n t t sur undias. passages; biasing the plug against the shoulder to seal Wall f t P a dl fl h S uld n tt n a the counterbored passage at the shoulder, and on both 49 d l' S f th l t h o n being fo med sidesof the intersection and the-passage which intersects with a relief P n t i i l and having one l the-counterbored passage at the intersection. p n g into lg Passage between and p v 4. A fluid relief device comprising a hollgw h i from both the shoulder and the screw so that said end having an internal partition dividing the housing interior Opening of h r i p s i i5 7 3 d by the i pressure and fixhapst ghambgrs, Saidpartition i plug upon deformation of the latter by screw pressure, formedwithan opening through which the pressure eha nr g s b i dire a ng eas' s m nt th th fit fiqmm nioateswith theexhaust chamber, valve means u r u g a l of thr ugh passage, between the re! 9 ally sealing the, opening in the partition, the housing lief P s op n n S 5 1d h other 6nd Q beingvforrned with integral bosses having passages com-i the, reliegpassagg i g Q l 1 1 Q Q h h municating ith thepressure chamber, a supplemental 50 hal1t b boss projecting laterally from the housing body adjacent a A u C t de i e 0 B i$lll l e n at d 9 the, partiti n, said-supplementalboss being formed .with W metal housing Yi l e t t fid e s; in an internal ntersecting passages one of which communicates internal transverse. P Fi t tille ou in with the pressure chamber and another of which commuterior into P essure and fl h st. chambsets p ctive y nicateswith the exhaust chamber, one of said passages d t t0 and r m e'f h attaching 6 e p ebeing formed with a counter-bore providing an annular tittQn b n formed h'a Openingthmush hi h the shoulder located between the intersection of the passages Pressure Chamber mm e with the exhaust c amand one of the chambers, a substantially cylindrical -debell a Spring biased Val? body n rm .5 the P formable and fusible plug disposed in the counterbore, t f O i the n having integral laterally P Said Plug a of greater length axially of thevcount'ep ectmg bosses each formed with a circular sectioned openq P ss han. diameter and than thevdistance from 7mg communicvatingrwith t hO fi 'i r one l the shoulder across the intersection of the1passages and boss ogenmg communicating. th h Pressure? Qh mh fthei am er ss sectional shape as the counterbored pasanother such s in m ml Q t nS t h i sage atsuch intersection, and a screw threaded into the hallst Chamber" the axes f a hosts: li ltl l l counterbored passage and actuatable to, bear axially Posed in Spaced t-RY P3151 planes 3 3 t th against; the; plug; to hold the latter axially against the longitudinal'axisrot the housing! 131 Pln in l l i i shoulderand on both'sides of the intersection whereby glided y the 'al z etr n ss e ed -l l l tolseal 'the QQunterbor'ed passage at'thc shoulder and the latter; s s nc th l 'th diame er of either one. passagewhichintersects' the, counterhored-passage'at the i q P il l lgsi s dipar l ioli bein ispe e z ubst nintersection. e r a ly w ll b een said parall l plane the housin ody being form d, w th external-wren h receiving flats which-extend onto an portionrof the housingilocated he-v ween the hails of. onesof the bosses along thehnusiug xisri ilt': least two of; the .-,w1=eneh :flats being inc oppositely i In a fluid relief device of the type comprising- 'a a planar end face parallel to the housing axis and to another of the wrench flats for receiving the housing between opposed wrench jaws with one such jaw engaged against the end face of the one boss and the other such jaw engaged against the one flat.

8. A fluid control device as defined in claim 7 in which the axes of the boss openings are disposed in planes substantially normal to one another and one of the bosses is disposed wholly on one side of the plane of one of the wrench flats.

9. A fluid control device as defined in claim 7 in which the axes of the boss openings intersect the housing axis.

10. A fluid control device as defined in claim 9 in which the axes of the boss openings are disposed in planes substantially normal to one another.

11. A fluid control device as defined in claim 7 in which the attaching end is formed with a through passage on the housing axis continuous with the pressure chamber and the threads on the attaching end are concentric to the housing axis so that the device is attached to a threaded fitting by relative rotation about the housing axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,687,209 Holmes Oct. 9, 1928 1,756,652 Maynard Apr. 29, 1930 1,854,750 Lovekin Apr. 19, 1932 2,040,776 Marvin May 12, 1936 2,210,555 Podolsky Aug. 6, 1940 2,305,519 Dunmire Dec. 15, 1942 2,353,191 Samiran July 11, 1944 2,516,387 Holicer July 25, 1950 2,590,656 Schnebel Mar. 25, 1952 2,622,613 McNeal Dec. 23, 1952 2,715,908 Huthsing Aug. 23, 1955 2,859,031 Hansen Nov. 4, 1958 

